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Principal Investigator:
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Robert D. Hienz, Ph.D.
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Organization:
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The Johns Hopkins University School of Medicine
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Assessing the biological consequences of living in the space radiation environment represents one of the highest priority areas of NASA research. Of critical importance is the need for an assessment of the vulnerabilities of the central nervous system (CNS) leading to functional neurobehavioral changes during long-term space missions, and the development of effective countermeasures to such risks. The present proposal addresses this need via the application of an innovative animal model to determine the long-term effects of radiation exposure on cognitive neurobehavioral function, and 2) the likely mechanisms of damage to the CNS following radiation exposure (e.g., radiation-induced changes in neurotransmitter system function).
To assess the likelihood of space radiation producing long-term functional changes in the CNS, neurobehavioral functions will be measured in rodents via animal tests analogous to human “vigilance” tests in humans. Cognitive neurobehavioral functions relevant to astronaut mission performance effectiveness will be assessed with a rodent analog of the Psychomotor Vigilance Test (PVT) currently used in space analog environments and by astronauts aboard ISS. Neurobehavioral functions to be examined include assessments of general motor function and speed, vigilance, inhibitory control ('impulsivity'), timing, motivation, and basic sensory function. Groups of animals will be trained on the rodent version of the PVT, following which they will be exposed to radiation and then re-tested periodically for up to 18 months post-exposure to assess potential long-term performance deficits. Likely mechanisms of damage to the CNS following radiation exposure will be examined via pre-radiation behavioral pharmacology studies as well as post-radiation behavioral pharmacology studies and neurochemical assessments (Western blots) of proteins relevant to neurotransmitter function and inflammation.
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